The NIDA IRP is developing and conducting extensive cutting edge research as part of its Clinical HIV Research Portfolio. The NIDA IRP HIV portfolio includes projects geared towards 1) reducing the incidence of HIV and 2) addressing the HIV-associated comorbidities, coinfections, and complications. NIDA IRP HIV projects seeking to reduce the incidence of HIV and supported by the NIDA IRP Clinical Core include HIV testing, counseling, and referral to treatment as indicated of over 400 individuals annually during screening for research participation at the NIDA IRP as well as a project utilizing geographical momentary assessment to determine activity space and social networks of HIV+ individuals to identify possible hotspots of HIV transmission and determine where to target prevention efforts such as vaccines, PrEP (Pre-exposure prophylaxis), testing, and addiction and Hepatitis C treatment. A third NIDA IRP HIV project supported by the NIDA Clinical Core is designed to reduce the incidence of HIV and address HIV-associated comorbidities, coinfections, and complications. This multi-institute collaboration looks to improve engagement in, adherence to, and retention in hepatitis C and buprenorphine treatment and PrEP (Pre-exposure prophylaxis) as HIV prevention. Dedicated clinical care and research support for these studies in the NIDA IRP HIV Research Portfolio is provided by the NIDA IRP Clinical Core and accounts for approximately 40% of our resource utilization. NIDA IRP HIV Portfolio-committed Clinical Core personnel at 40% effort include 5 nurses, 2 PAs, one physician (with a second one being added), and 6 research assistants. Additionally, the NIDA IRP Clinical Core through resources dedicated specifically to the NIDA IRP HIV Research Portfolio supports all laboratory testing, radiology, consult, and emergency care needs of all participants in NIDA IRP HIV Research Portfolio studies through a contract with the Johns Hopkins Bayview Medical Campus (JHBMC). The NIDA IRP Clinical Core provides human subjects protection and participant safety monitoring through Institutional Review Board (IRB), Data Safety and Monitoring Board (DSMB), and regulatory compliance support (1 IRB Administrator, 1 protocol navigator/compliance officer, 1 part-time statistician) of the NIDA IRP HIV Research Portfolio projects which due to the complicated medical and social histories of the participants require the highest level of monitoring. The NIDA IRP Clinical Core provides dedicated HIV Research Portfolio pharmacy support for all NIDA IRP HIV Research Portfolio projects (2 pharmacists + 1 pharmacy tech). Through a contract with Matthews Media Group (MMG), the NIDA IRP Clinical Core develops unique specific advertising and recruitment materials and screens for study eligibility all potential candidates for NIDA IRP HIV Research Portfolio projects.